Cigarette smoking is a major risk factor for the development of cardiovascular disease. Although nicotine is the addictive component of cigarette smoke, the vascular effects of nicotine in the absence of smoking are incompletely understood. The purpose of this study is to examine the vascular effects of transdermal nicotine in non-smokers. Specifically, brachial artery reactivity and nitric oxide levels will be compared in non-smokers in the absence and presence of transdermal nicotine. This study will be a double-blind, randomized, placebo-controlled trial. 44 healthy subjects will be enrolled in the parent protocol "Nicotine Patch Treatment as an Anorectic (IRB 951-97). Brachial reactivity and nitroc oxide levels will be tested at baseline (without nicotine), 6 hours after the initial patch application (acute effect) and after 8 weeks of patch treatment (chronic effect). If alterations in brachial artery reactivity are observed in response to nicotine, parallel changes in nitric oxide levels may be the mediator of this response.